Hi I made this tool that will show AKAs of your last opponent while you play (from LastReplay). It updates automatically as you play (after a game finishes). It's for 1v1, for other game modes it probably won't work.

The MMR shown is the highest one recorded for that name during this season, not their current MMR.

You can also show it on your stream if you like, see below for a demo stream. It's open source, written in Go.

download link:
https://github.com/innerspirit/bwakafinder/releases/tag/v1.0.0

screenshot:

stream demo:
https://www.twitch.tv/videos/2506624211?t=1h15m43s